Miller 15e ch15

© 2016 Cengage Learning. All Rights Reserved.
MILLER/SPOOLMAN
Environmental Science, 15e
G. TYLER MILLER | SCOTT E. SPOOLMAN
15
Air Pollution, Climate
Change, and Ozone
Depletion

• Atmospheric warming
– The gradual rise in the average temperature of
the surface atmosphere (over both land and sea)
– A key factor contributing to the melting of
Greenland’s glaciers, as well as in long term
climate change – a process caused primarily by
human activity, and which if left unchecked, will
have a harmful effect on global ecosystems and
the services they provide
Core Case Study: Melting Ice in Greenland

• Greenland (the world’s largest Island) is
mostly covered by glaciers – some as much
as 3.2km (2 miles) thick
• If climate change melted all of Greenland’s
ice, how much might sea level rise?
• Can you see effects of atmospheric warming
where you live?
Greenland’s Glaciers

• The atmosphere is composed of several
spherical layers
– The layer of air directly above the surface is the
troposphere, which supports life
– The layer above this is the stratosphere, which
contains the earth’s protective ozone layer
15.1 What Is the Nature Of the
Atmosphere?

• The troposphere contains the air we breathe
and is composed mainly of nitrogen and
oxygen – but also contains greenhouse
gasses (H20, CO2, CH4, N2O)
• The stratosphere is similar in composition to
the troposphere, but has much less water
vapor and contains the ozone layer
The Troposphere and Stratosphere

• Outdoor pollution includes industrial smog
(burning coal), photochemical smog (industrial
emissions and cars), and acid deposition
(coal-burning power/industrial plant and cars)
• Indoor pollution includes smoke/soot from
wood/coal fires, cigarette smoke, and
chemicals in building materials and cleaning
products
15.2 What Are the Major Air Pollution
Problems?

• Air pollution: atmospheric chemicals in high
enough concentrations to harm organisms,
ecosystems, and alter climate
– Natural: dust, wildfires, volcanoes, and plants
– Human activities: burning fossil fuels; car use
• Outdoor air pollutants:
– Primary: emitted directly into air
– Secondary: chemicals formed from primary
pollutants
Sources of Air Pollution

Natural and Human Inputs To Air
Pollutants

• Carbon oxides
• Nitrogen oxides and nitric acid
• Sulfur dioxide and sulfuric acid
• Particulates: suspended particulate matter
• Ozone
• Volatile organic compounds (VOCs)
– Hydrocarbons, methane, benzene, and liquid
solvents
Major Outdoor Air Pollutants

• Industrial smog: a mix of sulfur dioxide,
sulfuric acid, and particulates
– China, India, Ukarine, Czech Republic, Bulgaria
and Poland
• Photochemical smog: a mix of
primary/secondary pollutants/chemicals
formed in light activated reactions
– Los Angeles, Salt Lake City, Sydney, Sao Palo,
Bangkok and Mexico City
Smog

• Reduced by:
– Settling of particles heavier than air, cleansing by
rain/snow, salty sea spray from the oceans, wind
dilution and removal, chemical reactions in the
atmosphere
• Increased by:
– Urban structures that block winds, hills and
mountains that block valley ventilation, high
temperatures, emission of VOCs, grasshopper
effect, temperature inversions
Factors Influencing Outdoor Air Pollution

• Acidic compounds (H2SO4, HNO3, SO2
-4 and
NO-3) formed during wind dispersal of outdoor
pollutants can on descent result in far flung
acid deposition (a mix of wet/dry deposition)
– Wet deposition: acid rain/snow/cloud vapor;
happens slowly in distant downwind areas
– Dry deposition: acidic particles; happens quickly
close to industrial sources
Acid Deposition

Natural Capital Degradation: Acid
Deposition

• Harms crops, reduces plant productivity,
leaches essential nutrients from soil,
damages buildings, contributes to human
respiratory disease, and leaches toxic metals
into the environment that get biomagnified
into food webs
• Prevention is the best solution – reduce or
eliminate these pollutants from coal-fired
power and industrial plants
Acid Deposition: Problems and Solutions

• In less-developed countries, mainly from
indoor burning of wood, charcoal, dung, and
coal in open fires/poorly vented stoves
• In more-developed countries, from fumes
given off by building materials/furniture
– 11 common air pollutants are higher inside U.S.
buildings than outside
– Air pollution inside cars in congested traffic can
be almost 20 times higher than outside
Indoor Air Pollution

Indoor Pollutants In Modern Houses

• Respiratory system pollution protection:
– Hairs in your nose filter out large particles
– Mucus in upper respiratory tract traps smaller
particles/dissolves some gaseous pollutants
– Sneezing/coughing expel contaminated air
– Hair-like cilia in the upper respiratory tract
oscillate and transport mucus/pollutants to your
throat (swallowed or expelled)
– Prolonged or acute exposure to air pollutants can
break down these natural defenses
Air Pollution Is a Big Killer

• While there are many legal, economic, and
technological tools that can help us fight air
pollution, the best solution is prevention
15.3 How Should We Deal with Air
Pollution?

• Enact/regulate/enforce laws/standards
• Strengthen laws by:
– Prevention, further reducing and controlling
emissions (especially for cars and motorcycles),
setting stricter regulations for airports and
reducing indoor air pollution
• Authorizing/using emissions trading
– Dependent on how low initial cap is set/how often
this level is lowered to improve control
Reducing Outdoor Air Pollution

• Transition from using open fires/poorly vented
stoves in less-developed countries to more
efficient clay/well vented metal stoves and
solar cookers
• Ban indoor smoking and increase air
circulation in commercial buildings/homes
• Set stricter standards for emissions from
products designed/made for indoor use
• Use naturally based cleaning products
Reducing Indoor Air Pollution

• Scientific evidence indicates that atmospheric
warming is happening at a rate that will likely
lead to significant climate change
15.4 How Might the Earth’s Climate
Change In the Future?

• Weather: short-term changes in atmospheric
variables over hours or days
• Climate: average weather conditions and
patterns over the earth, or a specific region,
for a minimum of three decades
• As the earth’s average atmospheric
temperature rises, some areas get warmer,
others get cooler
Weather, Climate and Change

• Over the earth’s 3.5 billion year history
climate has changed many times
• For the last 100 thousand years, humans
have lived/developed in a reasonably steady,
inter-glacial (thawing) climate
• Over the last 200 years, atmospheric
temperatures have risen with urban growth
• The rate of climate change has been
accelerating since 1978
Climate Change

• How do we know it is happening now?
– Earth’s average global surface temperature
1.4 degrees F. than 1906
– Nine of the warmest years since 2000
– Glaciers/summer arctic sea ice are shrinking
– Melting permafrost; rising sea levels
– More atmospheric greenhouse gasses
– Migration of terrestrial/freshwater/marine
species towards the poles
More on Climate Change

• Greenhouse effect: lower atmospheric
warming caused by the reflection and
interaction of some of the earth’s incoming
solar radiation with molecules in the air
– Life on earth is dependent of this effect
• CO2/heat uptake by oceans helps to
moderate the earth’s average surface
temperature and slows climate change
• Cloud cover leads to atmospheric warming
The Greenhouse Effect, Oceans,and
Clouds

• The projected increases in atmospheric
temperatures can have long-lasting effects:
– Flooding
– Rising sea levels
– Shifts in the locations of croplands
– Wildlife habitats
– More extreme weather
15.5 What Are Some Possible Effects of a
Warmer Atmosphere?

• Worst case scenario: rising atmospheric
temperatures will likely lead to rising sea
levels, increased flooding, heat waves, forest
fires, grasslands will turn to dust bowls, rivers
will dry up, ecosystems will collapse, and ¼ of
the world’s species will go extinct
– Result: increased poverty and loss of food
security
Projected Consequences of Rapid
Atmospheric Warming

• Light-colored ice and snow in polar regions
helps to cool the earth by reflecting incoming
solar energy back into space (albedo effect)
– Melting ice and snow will expose darker land and
sea surfaces which reflect less sunlight and
absorb more solar energy – this warms the
atmosphere
– Freshwater will be added to the ocean – changing
chemistry?
Ice and Snow Likely To Melt

• Worst case scenario: a three foot rise could
have the following effects
– Degradation/destruction of coastal estuaries,
wetlands, coral reefs, and deltas
– Destruction of coastal fisheries
– Flooding of low-lying countries and cities, erosion
of low-lying barrier islands (especially in U.S.) and
submersion of island nations
– Saltwater invasion of coastal aquifers
Sea Levels

• Some regions will experience increased
chance of extreme drought, more intense heat
waves, and expansion of deserts
• Other regions will experience increased
flooding, precipitation (snow, rain), stronger
hurricanes and typhoons, and colder winters
Extreme Weather Could Become More
Common

• Up to 85% of the Amazon Rain Forest (a
major center of biodiversity) could be lost and
converted to tropical savannah
• 25-50% of the world’s species could face
extinction (especially polar bears, penguins,
and corals)
• Insect and fungi populations could explode
• As crop production falls, the diversity of crops
will also decrease
Climate Change Is Likely To Alter
Ecosystems

• More frequent and prolonged heat waves
could increase illnesses/the death rate
• Fewer people will die from cold weather
• With a warmer, more CO2 rich atmosphere,
disease transmitting insects, microbes/mold
populations will multiply
• Heavy photochemical smog will cause
pollution related respiratory problems and
often death
Climate Change May Threaten Human
Health

• If we cut waste and rely on new and
renewable energy resources, we can:
– Reduce greenhouse gas emissions
– Save money
– Improve human health
– Reduce the threat of climate change
15.6 What Can We Do To Slow Projected
Climate Change?

• The problem is complex, and both a global
and a long-term political issue
– Involves the uneven distribution of both beneficial
and harmful impacts of climate change
– Requires the reduction/phasing out of fossil fuel
use (which is controversial)
• Projected effects of climate change are still
uncertain
Dealing With Projected Climate Change Is
Difficult

Climate Change Tipping Points

• Strategies:
– Strictly regulate CO2 and CH4
– Phase out coal-burning power plants
– Tax CO2 or CH4 emissions/start energy taxes
– Use a cap-and-trade system
– Phase out subsidies/tax breaks for fossil fuel
industries and industrialized food production
• Offer subsidies for energy efficient technologies
– Increase development of alternatives
What Can Governments Do?

• Some countries, states, cities and private
companies are working to reduce their carbon
footprints
– Colleges and universities also reducing carbon
footprints
• We can prepare for climate change
– Focus the attention of relief organizations on
expanding mangrove forests, building shelters on
higher ground, and planting trees on slopes –
build structures higher off the ground
What Else Can Be Done?

• Reduced ozone levels in the stratosphere
coming from the widespread use of certain
chemicals is allowing more harmful ultraviolet
(UV) radiation to reach the earth
• By not producing and using ozone depleting
chemicals and adhering to international
treaties that ban these chemicals, we can
reverse ozone depletion
15.7 How Have We Depleted Ozone In
the Stratosphere?

• Ozone thinning stems from the overuse of
harmful chlorofluorocarbons (CFCs) known as
freons – used for coolants/air conditioning
• Ozone thinning allows:
– More biologically damaging UV-A/UV-B radiation
to reach earth’s surface, contributing to cataracts
and skin cancer
– Impairs/destroys phytoplankton
Ozone Depletion

• India invests in teaching solar cooking in
schools
– Part of a governmental five-year-plan to reduce
indoor air pollution by providing both the
technology (solar cookers) and training (classes
for assembling/cooking)
– Although solar cookers have been available in
India since 1982 – families try solar cooking and
then revert to traditional methods
•
Additional Case Study: Solar Cooking –
One Solution to Indoor Air Pollution

• By embedding classes in school curricula, the
government hopes to increase acceptance
and use of solar cooking
• How does a solar cooker work?
• What are three advantages and three
disadvantages of solar cookers?
• In India, what issues with solar cookers need
to be addressed to make usage more
practical?
More On Solar Cooking in India

• Solar cooking prevents a significant amount of
indoor air pollution
• Solar cookers rely on the sun and use an
unlimited, free, renewable energy resource --
which helps slow climate change.
• Projects for converting populations to solar
cooking are successfully underway in Africa,
South America and India – in preparation for
impacts of climate change
Solar Cooking and the Three Big Ideas

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